Electrical remote-control switch

ABSTRACT

An electrical remote-control switch assembly, comprising electromagnet means embodying a coil, a fixed core and a movable armature, and an electrical contact mechanism incorporating a movable blade, said armature being operatively connected with said movable blade. A control current circuit serves for pulse excitation of the armature, the coil being arranged in said control current circuit. According to the invention the core of the electromagnet possesses a substantially T-shaped configuration including a central leg portion which carries said coil and a transverse leg member, while the movable armature possesses a substantially U-shaped configuration embodying a pair of legs interconnected by a transverse web, said pair of legs extending externally of said coil at opposite sides thereof. The free ends of these legs are pivotably connected with opposite end portions of the transverse leg member of said T-shaped core, and stop means limit the pivotal movement of the armature between two stable terminal positions symmetrically situated relative to the central leg portion of said core. The contact mechanism is open when the movable armature assumes its one terminal position and closed when the armature assumes its other terminal position. A pivotable spring is mounted between the armature and a support point which is fixed relative to the core, this spring striving to displace the armature into each one of its two stable terminal positions and ensuring for an unstable condition of the armature in its central position intermediate such two stable terminal positions where the transverse web of the armature is located in front of the free end of the central leg portion of the core.

United States Patent Develay 541 ELECTRICAL REMOTE-CONTROL SWITCH 2,902,559, 9/1959 Morris ..335/l88 Primary Examiner-L. T. l-lix Attorney-Werner W. Kleeman [57] ABSTRACT An electrical remote-control switch. assembly, comprising Feb. 22, 1972 corporating a movable blade, said armature being operatively connected-with said movable blade. A control current circuit serves for pulse excitation of the armature, the coil being arranged in said control current circuit. According to the invention the core of the electromagnet possesses a substantially T- shaped configuration including a central leg portion which carries said coil and a transverse leg member, while the movable armature possesses a substantially U-shaped configuration embodying a pair of legs interconnected by a transverse web, said pair of legs extending externally of said coil at opposite sides thereof. The free ends of these legs are pivotably connected with opposite end portions of the transverse leg member of said T-shaped core, and stop means limit the pivotal movement of the armature between two stable terminal positions symmetrically situated relative to the central leg portion of said core. The contact mechanism is open when the movable armature assumes its one terminal position and closed when the armature assumes its other terminal position. A pivotable'spring is mounted between the armature and a support point which is fixed relative to the core, this spring striving to displace the armature into each one of its two stable terminal positions and ensuring for an unstable condition of the armature in its central position intermediate such two stable terminal positions where the transverse web of the armature is located in front of the free end of the central leg portion of the core.

oJO J g llll ll lmlmnm 1 ELECTRICAL REMOTE-CONTROL SWITCH BACKGROUND OF THE INVENTION The present invention relates to a new and improved electrical remote-control switch incorporating an electromagnet embodying a coil, a fixed core and a movable armature, which is operatively coupled with a movable lamellae or blade of an electrical contact mechanism, the coil being located in a control current circuit for pulse excitation, whereas the contact mechanism is provided for the purpose of being coupled with a load current circuit so that during successive closing of the control current circuit there is brought about an alternate opening and closing of the load current circuit.

Electrical switches of this type, particularly when used in the household, are associated with a number of drawbacks which will be considered hereinafter.

For instance, the power available for actuation of the contact mechanism is limited, since it is necessary to maintain within certain limits or tolerances both the spatial requirements of the electromagnetic coil in consideration of appropriate construction standards or norms as well as also the consumed electrical power in consideration of the heat buildup upon blocking ofthe control switch. Such limited power is especially then disadvantageous when the contact elements of the contact mechanism fuse or weld together during current flow and, therefore, require a certain force to again bring about separation of these contact elements.

Furthermore, the stroke of the movable armature of the magnetic circuit of the electromagnet is likewise limited, in order to be able to get by with a relatively low attraction force upon excitation of the magnet. Since, on the other hand, when the remote-control switch is switched off it is desirable that a rather large space exists between the contact elements of the contact mechanism, it is necessary to resort to the use of a lever mechanism which, while indeed increasing the stroke or lift of the armature, correspondingly reduces the contact operating force.

The movable armature of the electromagnet generally comes into contact with the core of the electromagnet, in order to obtain a maximum force of attraction. Consequently, during excitation of the electromagnet there always occurs an impact, rendering impossible noiseless operation of the remote-control switch, and therefore, precludes use of the remote-control switch for a number of purposes.

Moreover, the use of alternating current as the power source for excitation of the electromagnet oftentimes causes an undesired humming during the excited condition of the electromagnet.

SUMMARY OF THE INVENTION Accordingly, there is still present a real need in the vart for an electrical remote-control switch which is not associated with the aforementioned drawbacks existing in the state-ofthe-art switches of this type. Therefore, a primary object of the instant invention is to provide an improved construction of remote-control switch which reliably overcomes the abovenoted drawbacks of the prior art constructions and effectively fulfills the existing need in the art.

Still a further significant object of the invention is the construction of a, remote-control switch which enables overcoming the aforementioned drawbacks in a relatively simple manner.

Yet a further object of this invention which is equally important relates to a remote-control switch of the type mentioned which is relatively simple in construction, economical to manufacture, extremely reliable in operation, and not readily subject to breakdown.

Now, in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the remote-control switch of the present invention is generally manifested by the features that the core of the electromagnet possesses the form of the letter T, the central leg of which carries the coil. The movable armature possesses the form of the letter U, both legs of which extend externally of the coil at opposite sides thereof, with the leg ends or terminal portions each being pivotably mounted at an end portion of the transverse leg of the T-shaped core. The invention further contemplates the provision of stop means or limit stops for limiting the degree of pivoting of the armature, these stop means being arranged between two stable terminal positions symmetrically situated relative to the central or middle leg of the core. In one terminal position of the armature the contact mechanism is open, and in the other terminal position thereof the contact mechanism is closed. A tiltable or pivotable spring is arranged between the armature and a support point which is fixed relative to the core, this pivotable spring tends to displace the armature into each one of the two terminal positions and ensures for unstable condition of the armature in its central position, in which'the U-web, i.e., central web of the U-shaped armature is located in front of the free end of the central leg of the T-shaped core.

With this inventive construction of remote-control switch the U-web of the armature assumes a position laterally of the free end of the central leg of the core of the electromagnet in each of both stable terminal positions, so that during a pulselike brief excitation of the electromagnet the U-web of the armature is attracted towards its unstable or labile central position and thereafter, upon termination of the pulselike excitation, owing to its mechanical inertia rocks past the mentioned unstable central position, whereupon the tiltable spring rocks or tilts the armature into the oppositely situated stable terminal position. During the next pulselike excitation of the electromagnet the armature rocks back in completely analogous manner into its first stable terminal position. Thus, the U-web of the armature moves during each brief excitation of the electromagnet over and past the free end of the central leg of the core of the electromagnet without contacting such. The arrangement and construction of the electromagnet considered above as well as that of the movable armature affords a relatively space-saving construction, rocking of the armature from the one into the other stable terminal position requiring relatively little energy. Additionally, the mode of operation of the remote-control switch is practically independent of the spatial orientation of the remote-control switch.

BRIEF DESCRIPTION OF THE DRAWINGS according to one embodiment of the present invention,

wherein for the purpose of exposing the internal structure thereofa cover housing member has been removed;

FIG. 1A is a top plan view of the electromagnet and the movable armature in one of its stable terminal positions, as viewed from the top of FIG. 1; and

FIGS. 2 and 3 are respective electrical schematic circuit diagrams of two different embodiments of the electrical components and the current circuit ofthe switch of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Describing now the drawings, it will be understood that the remote-control switch depicted in FIG. 1 possesses a socket 10 having a substantially circular-shaped supporting base, this socket 10 being formed of a suitable insulating material, preferably plastic. At the periphery of the socket 10 there are provided connection terminals or clamps 11, 12, 13, 14 and 15.

An electromagnet 20 is arranged in an elongate recess 10a of the socket l0, electromagnet 20 being equipped with a coil or winding 21. The magnetic circuit of the electromagnet 20, for instance, consists of soft iron and embodies a fixed core 22, 23 and a movable armature 24. The fixed core 22, 23 possesses the configuration or shape of the letter T incorporating a cylindrical rod 22 supporting the coil 21 and a transverse member 23 connected with the lower end of this rod 22. Rod 22 forms the vertical central leg of the T-shaped core, while the transverse member or element 23 forms the horizontally extending transverse leg of this T-shaped core.

Now, the movable armature 24 is formed from a flat strip which is twice flexed and is in the form of the letter U, thus embodies two parallel legs 24a and a central web 24b.;-Both of the parallel legs 24a are arranged externally of the coil'2l at oppositely situated sides thereof. The terminal regions or free ends of the U-legs 24a are pivotably mounted at the end portions of the T-transverse leg' 23, for instance through the provision of knife edges 240 formed at the free ends of the U- legs 24a which engage with appropriate notches or grooves 23a of the T-transverseleg 23. The length of each of the legs 24a of the movable armature 24 is chosen such that the U-web 2412, that is, the transverse extending web of the armature can move in front of the free upper end of the central rod 22 from one to the other side of the recess a of the socket 10 without contacting this rod 22. The U-web 24b of the movable armature 24 further possesses at both sides thereof semicircular configured recesses 24d, as best observed by referring to FIG. 1A, the reasons. for which will be more fully explained hereinafter.

Continuing, it will be seen that a notch 242' is located between these recesses 24d and this notch 24:: is located at the central portion of the transverse web 24b. A tiltable or pivotable spring 25 is pivotably mounted at one end in this notch or depression 24e, spring 25 possessing the configuration of the Greek symbol omega capitalized. The other end of this tiltable spring 25 supports itselfin a notch or recess 10b provided at a wall of the recess 10a of the socket l0, and specifically at a location which is aligned with the longitudinal axis of the rod 22, so that the tiltable spring 25 ensures for an unstable condition of the movable armature 24 when it assumes its central or middle position where the U-web 24b is located in front of the free end of the upstanding rod 22. Pivotal or tiltable spring 25 strives to either force the armature 24 out of its unstable central position into the one or the other of two stable terminal positions, defined by elastically resilient stop or impact members 26 and 27. The stops 26 and 27 are symmetrically arranged relative to the rod 22 and, for instance, can be formed of rubber.

Continuing, it will be observed by referring to FIG. 1 that an elastically flexible blade or lamellae 31, for instance possessing a substantially L-shaped configuration, is fixedly connected with the connection terminal 12. Blade 31 carries a contact element or rivet 32 and bears in a prestressed deformed condition against a stop 33 secured to the socket or housing 10. A second, for instance, straight blade or lamellae 34 is rigidly or fixedly connected with the connection terminal 13. This blade 34 likewise carries a contact ele'ment'or rivet 35 and is operatively connected with a leg 24a of the movable armature 24 of the electromagnet through the agency of a rod 36. This rod or bar 36 consists of insulating material, for instance plastic. The blades 31 and 34 and the cooperating contact elements or rivets 32 and 35 collectively form an electrical contact mechanism. More particularly, the second blade 35 is movable through the agency of the rod 36 under the action of the electromagnet 20, in order to close or open the contact between the contact rivets or elements 32, 35.

In a free portion of the recess 10a receiving the electromagnet 20 and in the other recesses 10c and 10d of the socket or housing 10 there are located an electrical resistance or resistor 41, a thermal bimetallic-protective circuit breaker, a rectifier diode 43 and a capacitor 44. The electrical connection of these components and the coil 21 with the terminals 11 to 15 and with one another has been shown in FIG. 2, in which the same components have been conveniently designated with the same reference characters employed in FIG. 1.

' minals l1 and 12 are provided for connection with a suitable source of alternating current A, the terminals 11 and 13 for connection to a load or consumer L, so that the load current circuit can be supplied from the current source A via the contact mechanism 31 to 35. The coil 21 of the electromagnet 20 is connected between the terminals 11 and 15, and the capacitor 44 is connected between the terminals 11 and 14. The terminals l4 and 15 also serve the purpose of connecting an external pushbutton switch B, or equivalent structure. The coil 21, the capacitor 44, the pushbutton switch B and their connections collectively form a control current circuit for exciting the electromagnet 20. Arranged in series between the terminals 12 and 14 are the resistor 41, the bimetallic-protective circuit breaker 42 and the rectifier diode 43. Theselast-mentioned components collectively form a charging current cir- I cuit for charging the capacitor 44 from the current source A.

The mode of use and operation of the described remotecontrol switch is as follows: I v

In the preparatory state of the equipment the capacitor 44 is charged with a weak rectified current via the resistor 41, the bimetallic-protective circuit breaker 42 and the diode 43, this current being delivered by the current source A. Upon depressing the pushbutton switch B a sudden discharge of the capacitor 44 across the coil 21 causes an impulse excitation of the electromagnet 20 and a forcible attraction of the movable armature 24 in the direction towards the rod 22 of the core 22, 23 of the electromagnet 20. The semicircular configured recesses 24d of the U-web 24b of the movable armature 24 as illustrated in FIG. 1A and in dotted lines in FIG. I serve the purpose of providing for the appearance of a starting attraction force between the armature 24 and the rod 22 which is as high as possible under the given conditions. The current pulse flowing through the coil 21 is indeed quite brief, yet however is sufficient to attract the movable armature 24 against the force of the tiltable spring 25 until it reaches the unstable or labile central or middle position, where the kinetic energy imparted to the armature 24 is sufficient to further move the armature across its unstable central position. Thereafter, the tiltable spring 25, which opposes the first portion of the movement of the armature 24, then accelerates the second portion of the armature movement until the armature has reached its oppositely situated stable terminal position at the stop 27. With the described positional change of the armature 24 the movable blade 34 is actuated by means of the rod 36 in the same direction, so that the electrical contact between the contact elements 32 and 35 is closed. If the pushbutton switch B is released and thus the discharge current circuit of the capacitor 44 is interrupted then, once again, charging of the capacitor 44 occurs. By again pressing the pushbutton switch B the, capacitor 44 which has again charged-up in the meantime, again discharges across the coil 21, resulting in an impulselike excitation of the electromagnet 20 and the tilting back of the armature 24 into its first stable terminal position at the stop 26. Consequently, the movable blade 34 is displaced by the rod 36 in such a way that the contact between the contact elements 32 and 35 again opens.

The force exerted via the connection' rod 36 upon the movable blade 34 is a multiple of the force exerted by the electromagnet 20 upon the movable armature 24, corresponding to the relationship or ratio of the longer to the shorter lever arm of the armature 24. Therefore, the force exerted upon the movable blade 34 is sufficient to bring about separation of the contact elements 32 and 35, even if these contact elements have slightly fused or welded to one another following the preceding closing of the current circuit.

If the pushbutton switch B is continuously depressed or for some other reason remains closed, with time it would be possible that an impermissible heating-up of the coil 21 and the resistor 41 could occur, since these components then would be continuously electrically coupled with the current source A. Now, in order to prevent damage because of intensified heat buildup, there is provided the bimetallic-protective circuit breaker 42 which is heated by the thermal energy or heat developed by the resistor 41 and after a certain period of time automatically interrupts in known fashion the current circuit, Even if a short-circuit condition occurs at the capacitor 44 the bimetallic-protective circuit breaker 42, after a certain period of time, comes into play because of the heating-up of the resistor 41, so that the current circuit is interrupted.

FIG. 3 depicts a slightly modified construction of the described switch, wherein the components corresponding to those of the switch construction of FIGS. 1 and 2 have been conveniently designated with the same reference characters. The difference between the modified switch of FIG. 3 and that of FIGS. 1 and 2 resides practically only in the features that the load current circuit coupled with the terminals 12 and 13, in the case of the switch construction of FIG. 3, is independent of the control current circuit of the coil 21. The control current circuit of the coil 21,-as shown in FIG. 3, is coupled via the terminals 11 and 16 with a direct current source A and via the terminals 14 and 15 is coupled with an external control switch B. Control switch B is designed to provide for the delivery of contact pulses or impulses, so that during each actuation of the switch B the control current circuit is only briefly closed. Between the terminals 14 and 16 there is located a bimetallic-protective circuit breaker 42 and a resistor 41' serving as the heating element for the protective switch42. The mode of operation of the embodiment of FIG. 3 is similar to the first described embodiment of FIGS. 1 and 2. Instead of the electrical energy stored by the capacitor 44, the coil 21 of the arrangement of FIG. 3 is always directly excited by a current pulse from the direct current source A when the control switch B is actuated. The bimetallic-protective circuit breaker 42 serves for the automatic interruption of the control current circuit for the event that the control switch B should remain in its closed position.

In the embodiment of FIG. 3 the auxiliary current circuit A, if desired, can be an alternating current source if the duration of the period of the alternating current possesses an order of magnitude which corresponds to the duration of the m0- mentary action or working of the switch B.

If desired, the thermal bimetallic-protective circuit breaker 42 can be omitted in both described embodiments.

While there is shown and described present preferred embodiments of the invention, it is to be distinctlyunderstood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.

What is claimed is:

I. An electrical remote-control switch assembly, comprising electromagnet means embodying a coil, a fixed core and a movable armature, an electrical contact mechanism incorporating a movable blade, said armature being operatively connected with said movable blade, a control current circuit for pulse excitation, said coil being arranged in said control current circuit, said contact mechanism being provided for electrical coupling with a load current circuit so that upon successive closing of said control current circuit there is brought about an alternate opening and closing of the load current circuit, said core of said electromagnet possessing a substantially .T-shaped configuration including a central leg portion which carries said coil and a transverse leg member, said movable armature possessing a substantially U-shaped configuration embodying a pair of legs interconnected by a transverse web, said pair of legs extending externally of said coil at opposite sides thereof, the free ends of said legs being pivotably connected with opposite end portions of said transverse leg member of said T-shaped core, stop means for limiting the pivotal movement of said armature between two stable terminal positions symmetrically situated relative to said central leg portion of said core, said contact mechanism being open when said movable armature assumes its one terminal position and being closed when said movable armature assumes its other terminal position, a pivotable spring mounted between said armature and a support point which is fixed relative to the core, said pivotal spring striving to displace said movable armature into each one of its two stable terminal positions and ensuring for an unstable condition of the armature in its central position intermediate said two stable terminal positions where said transverse web of said substantially U-shaped armature is located in front of the free end of said central leg portion of said core.

2. The remote-control switch assembly as defined in claim 1, wherein said control current circuit embodies a capacitor, a charging current circuit, said capacitor being electrically coupled with said charging current circuit, and connection terminals for connecting an external control switch, said external control switch when closed causing discharge of said capacitor across said coil.

3. The remote-control switch assembly as defined in claim 2, wherein said charging current circuit comprises a resistor, rectifier means and connection terminals for connection with a source of alternating current.

4. The remote-control switch assembly as defined in claim 2, wherein said charging current circuit contains a thermalprotective circuit breaker.

5. The remote-control switch assembly as defined in claim 1, wherein said control current circuit is equipped with connection terminals for connecting an external control switch for delivering impulses for operating the contact mechanism, and further connection terminals for connection to an electrical energy source.

6. The remote-control switch assembly as defined in claim 5, wherein said control current circuit contains a thermal-protective circuit breaker. 

1. An electrical remote-control switch assembly, comprising electromagnet means embodying a coil, a fixed core and a movable armature, an electrical contact mechanism incorporating a movable blade, said armature being operatively connected with said movable blade, a control current circuit for pulse excitation, said coil being arranged in said control current circuit, said contact mechanism being provided for electrical coupling with a load current circuit so that upon successive closing of said control current circuit there is brought about an alternate opening and closing of the load current circuit, said core of said electromagnet possessing a substantially T-shaped configuration including a central leg portion which carries said coil and a transverse leg member, said movable armature possessing a substantially U-shaped configuration embodying a pair of legs interconnected by a transverse web, said pair of legs extending externally of said coil at opposite sides thereof, the free ends of said legs being pivotably connected with opposite end portions of said transverse leg member of said Tshaped core, stop means for limiting the pivotal movement of said armature between two stable terminal positions symmetrically situated relative to said central leg portion of said core, said contact mechanism being open when said movable armature assumes its one terminal position and being closed when said movable armature assumes its other terminal position, a pivotable spring mounted between said armature and a support point which is fixed relative to the core, said pivotal spring striving to displace said movable armature into each one of its two stable terminal positions and ensuring for an unstable condition of the armature in its central position intermediate said two stable terminal positions where said transverse web of said substantially Ushaped armature is located in front of the free end of said central leg portion of said core.
 2. The remote-control switch assembly as defined in claim 1, wherein said control current circuit embodies a capacitor, a charging current circuit, said capacitor being electrically coupled with said charging current circuit, and connection terminals for connecting an extErnal control switch, said external control switch when closed causing discharge of said capacitor across said coil.
 3. The remote-control switch assembly as defined in claim 2, wherein said charging current circuit comprises a resistor, rectifier means and connection terminals for connection with a source of alternating current.
 4. The remote-control switch assembly as defined in claim 2, wherein said charging current circuit contains a thermal-protective circuit breaker.
 5. The remote-control switch assembly as defined in claim 1, wherein said control current circuit is equipped with connection terminals for connecting an external control switch for delivering impulses for operating the contact mechanism, and further connection terminals for connection to an electrical energy source.
 6. The remote-control switch assembly as defined in claim 5, wherein said control current circuit contains a thermal-protective circuit breaker. 